Scrapbook and photo archive of Dr. Frederick Finch Strong. Strong was inventor of the glass vacuuum "Violet Ray" electrode commonly used for electrotherapy using Tesla Coils in 1896. He wrote a historical book "High Frequency Currents" in 1908, and spent much of the 1920s and 30s lecturing around the country on Theosophy, the occult, spiritualism, and medicine.
